Addition Strategies

Fact Fluency Games: Addition

Counts All

This is the earliest stage of understanding addition. Children count from one to find the sum.  They often use manipulatives or count on their fingers.
For   5 + 2, a child will count, “1, 2, 3, 4, 5, 6, 7.”
 

Zeros & Ones

Children understand that when you add any number to zero, the sum stays the same. When adding one, the sum grows by 1.
 
5 + 0= 5
5 + 1 = 6

Near Doubles (Doubles +/- 1)

Once your child is confident with doubles facts, he/she can be led to recognize doubles plus or minus one facts as close neighbors.   
2+3         3+4
4+5         5+6
6+7          7+8
8+9
 

Add Ten

Students recognize that adding a single digit number to 10 means 10 and some more.   This understanding helps children to use strategies to add double digit numbers with ease by using methods that involve place value splitting.
6 + 10 = 16
 

Use known facts / Break Apart

However, if a child has mastered ten facts, he or she could choose to manipulate other facts into ten facts.    

8 + 5 = 8 +2 + 3

The 5 could be broken into 2 + 3.  The 2 can be quickly added to 8 and now we have an easier fact: 10 + 3.  
 

Counts On

Students understand that it is faster to start with the larger addend and count on.
3 + 6 = 6, 7, 8, 9
 

Doubles

Students come to recognize doubles facts as ‘numbers that have a partner’ on the number rack, or you can see them in a mirror.  They should also notice that sums are always even.  Committing these facts to memory will aid in the next strategy.

3 + 3 = 6
7 + 7 = 14
8 + 8 = 16
9 + 9 = 18 
 

Make 10

Begin to recognize “partners” of numbers that make 10.  Since our number system is based on 10, when children are good at recognizing the combinations (i.e. 2 + 8; 4 + 6) they can begin to apply this to larger computation (i.e. 12 + 38; 24 + 17) 
1 + 9
2 + 8
3 + 7
4 + 6
5 + 5
 

Near Ten (Add 9)

Since adding 10 to any number is ‘easy’, students quickly become comfortable seeing 9 as a next-door neighbor to 10.  They can add 10 and then take 1 away.   Or he/she can choose to take 1 from the other addend to ‘make the 9 into a 10’.  

9 + 4 = 10 + 4 -1 = 13